Success in OASIZ 301 Phase 3 Trial and Meeting Primary Endpoint

In the top-line results of the phase 3 clinical trial (OASIZ 301) of dazodalibep conducted by Amgen in 651 patients with Sjögren's disease accompanied by moderate to severe systemic disease activity, the primary endpoint was met. At the 48-week treatment time point, patients demonstrated statistically significant and clinically meaningful improvements in European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI) scores compared to the placebo group. The improvement effect was observed early from the fourth week of administration and remained stable throughout the 48-week treatment period. The most common adverse reactions included pharyngitis, urinary tract infection, hypertension, and infusion-related reactions, which were mostly mild to moderate in severity, thereby establishing an excellent safety profile.

Establishing the Clinical Efficacy of CD40 Ligand (CD40L) Antagonism

Dazodalibep is a non-antibody-based fusion protein that inhibits lymphocyte activation by targeting the CD40 ligand (CD40L, CD154), which is a key signaling pathway in T-cell and B-cell interaction. Sjögren's syndrome involves the immune system attacking exocrine glands such as salivary and lacrimal glands, causing dry mouth and eyes as well as systemic organ involvement, yet there are currently no FDA-approved disease-modifying antirheumatic drugs (DMARDs) for this unmet medical need. This clinical success holds significant academic and industrial value by successfully validating the therapeutic efficacy and safety of the CD40L inhibition mechanism in a late-stage clinical phase, a mechanism that was previously difficult to develop due to thromboembolic side effect concerns.

Rebound in Value of Horizon Acquisition Pipeline and Mitigation of R&D Risk

This achievement is the most encouraging clinical outcome among the assets in the pipeline resulting from Amgen's $27.8 billion acquisition of Horizon Therapeutics in 2023. Previously, Amgen discontinued the development of adezkibart, an FLT3L-targeted antibody from its Horizon acquisition portfolio, after a Phase 2 futility assessment failed. Global big pharma companies such as Astellas and Sanofi have also withdrawn related pipelines, encountering difficulties in disease research. Dazodalibep is a core asset secured by Horizon through its $3 billion acquisition of Viela Bio in 2021; this success has completely dispelled the uncertainty regarding R&D cost recovery associated with the large-scale M&A.

First-in-Class Competition with Novartis' Ianalumab

The global Sjögren's syndrome market is currently entering a rapid transition period, moving from a symptomatic treatment-centered market worth $200 million–$600 million annually to a disease-modifying targeted biologic market worth over $1 billion–$3 billion. The most direct competitor is Novartis' BAFF-R-targeting monoclonal antibody ianalumab, which has demonstrated positive Phase 3 results, and both companies are competing fiercely for the title of the first-ever treatment for Sjögren's syndrome. Amgen plans to complete its follow-up Phase 3 trial (OASIZ 303) for patients with mild-to-moderate systemic disease within this year and proceed with a Biologics License Application (BLA) by integrating data from the long-term extension study (OASIZ 304).